JP2000313905A - Composite materials and various applications - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a composite material having high thermal conductivity, a low coefficient of thermal expansion, and high plastic workability, and various uses such as a semiconductor device using the same. The composite material of the present invention is made of a Cu alloy containing 5 to 80% by volume of cuprous oxide particles, and is made of an isotropic pressure sintered body. The coefficient of thermal expansion from room temperature to 300 ° C. is 5 × 10 ^{−6 to} 17 × 10 ⁻⁶ / ° C., the thermal conductivity is 30 to 375 W / m · K, and the conductivity is 10 to 8
5% IACS is obtained. It is applied to a heat sink of a semiconductor device, an electrode plate of an electrostatic attraction device and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel composite material having low thermal expansion and high thermal conductivity, a method for producing the same, and various uses such as a semiconductor device using the same.

[0002]

2. Description of the Related Art Power electronics is a technology related to the conversion and control of power and energy by an electronic device, in particular, a power electronic device used in an on / off mode and a power conversion system as an application technology thereof.

[0003] For power conversion, power semiconductor devices having various on / off functions are used. This semiconductor device includes a rectifier diode having a built-in pn junction and having conductivity in only one direction, and a thyristor, a bipolar transistor,
MOSFETs and the like have been put to practical use, and furthermore, insulated gate bipolar transistors (IGBTs) and gate turn-off thyristors (GTOs) having a turn-off function by a gate signal have been developed.

[0004] These power semiconductor elements generate heat when energized, and the amount of heat generated tends to increase as their capacity and speed increase. In order to prevent the deterioration of the characteristics of the semiconductor element and the shortening of the service life due to the heat generation, it is necessary to provide a heat radiating section to suppress the temperature rise in the semiconductor element and its vicinity. Copper is generally used as a heat dissipating member because it has a large thermal conductivity of 393 W / m · K and is inexpensive. However, since the heat radiation member of the semiconductor device including the power semiconductor element is bonded to Si having a coefficient of thermal expansion of 4.2 × 10 ⁻⁶ / ° C., a heat radiation member having a coefficient of thermal expansion close to this is desired. Copper has a large coefficient of thermal expansion of 17 × 10 ⁻⁶ / ° C., and thus has poor solder jointability with a semiconductor element. It is provided between heat dissipating members.

On the other hand, integrated circuits (ICs) in which electronic circuits are integrated on one semiconductor chip are classified into memories, logics, microprocessors, and the like according to their functions.
Here, the power semiconductor element is called an electronic semiconductor element. The degree of integration and the operation speed of these semiconductor elements have been increasing year by year, and accordingly, the amount of heat generated has also increased. by the way,
In general, an electronic semiconductor element is housed in a package for the purpose of shutting it off from the outside air and preventing failure and deterioration.
Many of these are a ceramic package in which a semiconductor element is die-bonded to ceramics and sealed, and a plastic package in which the semiconductor element is sealed with resin.
Also, in order to support high reliability and high speed, a multi-chip module (MCM) in which a plurality of semiconductor devices are mounted on one substrate is also manufactured.

The plastic package has a structure in which a lead frame and terminals of a semiconductor element are connected by a bonding wire, and this is sealed with a resin. In recent years, with an increase in the amount of heat generated by a semiconductor element, a package in which a lead frame has heat dissipation properties and a package in which a heat dissipation plate for heat dissipation is mounted have appeared. For heat dissipation, a copper-based lead frame or a heat radiating plate having a large thermal conductivity is often used, but there is a concern about a problem due to a difference in thermal expansion from a package constituent material such as a chip or a sealing resin.

On the other hand, the ceramic package has a structure in which a semiconductor element is mounted on a ceramic substrate on which wiring is printed, and is sealed with a metal or ceramic cap. Furthermore, Cu-Mo or Cu
-W composite material or Kovar alloy is joined,
Although it is used as a heat sink, each material has low thermal expansion or high thermal conductivity,
Low cost is required.

The MCM has a structure in which a plurality of semiconductor elements are mounted on a thin film wiring formed on a substrate made of Si, metal, or ceramics by a bare chip, placed in a ceramics package, and sealed with a lid. When heat dissipation is required, a heat sink or a heat dissipation fin is installed on the package. Copper or aluminum is used as a metal substrate material, which has the advantage of high thermal conductivity, but has a large coefficient of thermal expansion and poor compatibility with semiconductor elements. For this reason, Si or aluminum nitride (AlN) is used for the substrate of the highly reliable MCM. Further, since the heat radiating plate is bonded to the ceramic package, a material having good compatibility with the package material in terms of the coefficient of thermal expansion and having a large thermal conductivity is desired.

[0009]

As described above, any semiconductor device having a semiconductor element mounted thereon generates heat during its operation, and if stored, the function of the semiconductor element may be impaired. Therefore, a heat radiating plate having excellent thermal conductivity for dissipating generated heat to the outside is required. The heat sink is
Since the semiconductor element is bonded directly or via an insulating layer, the semiconductor element is required to have not only thermal conductivity but also thermal expansion.

Currently used semiconductor elements are mainly S
i and GaAs. These thermal expansion coefficients, respectively ^{2.6 × 10 -6 ~3.6 × 10 -6} /℃,5.7×10 -6
6.9 × 10 ⁻⁶ / ° C. Heat sink materials having a thermal expansion coefficient close to these include AlN, SiC, Mo,
Although W, Cu-W, etc. are known, since these are single materials, it is difficult to arbitrarily control the heat transfer coefficient and the thermal conductivity, and the workability is poor and the cost is high. There is. JP-A-8-78578 discloses C
A u-Mo sintered alloy is disclosed in Japanese Unexamined Patent Publication No. 9-181220.
W-Ni sintered alloy, Japanese Unexamined Patent Publication No. 9-209058 discloses Cu-S
iC sintered alloy, Japanese Patent Application Laid-Open No. 9-15773 discloses Al-SiC
Has been proposed. These conventionally known composite materials can control the heat transfer coefficient and the heat conductivity over a wide range by changing the ratio of both components, but have low plastic workability,
It is difficult to manufacture thin plates, and the number of manufacturing steps is further increased.

An object of the present invention is to provide a composite material having low thermal expansion and high thermal conductivity and excellent in plastic workability, a semiconductor device using the same, a radiator plate thereof, an electrostatic chuck device and an electrode plate thereof. With the goal.

[0012]

SUMMARY OF THE INVENTION The present invention resides in an isotropically pressed sintered body, and preferably comprises copper ( _II ) oxide of 5 to 8%.
0% by volume, the balance being composed of copper (Cu) and unavoidable impurities, having a structure in which the Cu ₂ O phase and Cu phase are dispersed, and having a coefficient of thermal expansion of 5 × 10 ⁻⁶ at room temperature to 300 ° C.
~ 17 × 10 ^-6 / ° C, thermal conductivity 30 ~ 375W / m ·
K and a conductivity of 10 to 85% IACS.

This composite material is made of copper oxide (Cu)
₂ O) in an amount of 5 to 80% by volume and a particle size of 50 μm or less, preferably 10 μm or less, more preferably 50% by volume.
The following are particle diameters of 50 to 200 μm, the remainder is 50 μm or less, the remainder is composed of copper (Cu) and unavoidable impurities, and has a structure in which the Cu ₂ O phase and Cu phase are oriented. Expansion coefficient is 5 × 10 ^{-6 to} 17 × 10
⁻⁶ / ° C., thermal conductivity of 30 to 375 W / m · K, electrical conductivity of 10 to 85% IACS, thermal conductivity and anisotropy of conductivity, thermal conductivity in the alignment direction Preferably, the conductivity and conductivity are higher than those in the direction perpendicular to the orientation direction.

In the composite material according to the present invention, Au, Ag, Cu, Al having high electric conductivity is used as a metal.
u is most excellent in that it has a high melting point and high strength. Moreover, a stable conventional SiC different as inorganic compounds extremely hardness relative to the above-mentioned base metal, after sintering at a relatively soft particles rather than compounds such as Al ₂ O _3, 20~150 ℃
Is preferably 5.0 × 10 ^−6.
/ ° C. or lower, more preferably 3.5 × 10 ⁻⁶ / ° C. or lower, and a Vickers hardness of 300 or lower.
By using soft inorganic compound particles in this way, high plastic workability by hot and cold after sintering can be obtained, and in particular, since these can be rolled, the production time is shortened and comparison is made. A very thin plate can be obtained. Copper oxide, tin oxide, lead oxide, nickel oxide and the like can be considered as the inorganic compound particles. However, soft copper oxide having the smallest coefficient of thermal expansion, especially copper oxide (C)
u ₂ O) is preferred. The obtained sintered body has a theoretical density of 95.
% Or more is preferable.

Further, the composite material of the present invention is made of SiC, Al ₂
It is preferable to contain 5% by volume or less of fine ceramic particles having a Vickers hardness of 1000 or more and a hard average particle size of 3 μm or less, such as O ₃ , to further strengthen them.

In the method for producing a composite material according to the present invention, a mixed powder containing cuprous oxide (Cu ₂ O) and copper (Cu) is filled in a metal container, degassed and sealed, and then heated at 700 to 1050 ° C. A step of isostatic pressing by a hot isostatic pressing press (HIP), or further comprising a step of plastic working at least one of cold and hot, and a subsequent annealing step. And

Further, the method for producing a composite material according to the present invention is characterized in that the mixed powder containing 2.7 to 48.8% by volume of copper (CuO) and the balance of copper (Cu) and unavoidable impurities After filling, degassing and sealing the container, 700 ° C-1050
It is characterized by including a sintering step by hot isostatic pressing (HIP) at ℃, a step of plastic working at least one of cold and hot, and a subsequent annealing step.

According to the present invention, there is provided a heat sink for a semiconductor device, comprising a composite material as described above. Further, there is provided a heat sink for a semiconductor device having a Ni plating layer on a surface thereof.

The present invention comprises a plurality of insulating substrates mounted on a heat sink, and a plurality of semiconductor elements mounted on each of the insulating substrates, wherein the insulating substrate is provided with conductor layers on upper and lower surfaces. , And is directly joined to the heat sink through the conductor layer.

According to the present invention, in a semiconductor device having an insulating substrate mounted on a radiator plate and a semiconductor element mounted on the insulating substrate, the radiator plate comprises the radiator plate described above.

The present invention comprises a semiconductor element mounted on a heat sink, a lead frame connected to the heat sink, and a metal wire for electrically connecting the lead frame and the semiconductor element. In a semiconductor device in which the heat sink is resin-sealed, the heat sink is made of the heat sink described above.

According to the present invention, there is provided a semiconductor device comprising: a semiconductor element mounted on a heat sink; a lead frame connected to the heat sink; and a metal wire for electrically connecting the lead frame and the semiconductor element. In a semiconductor device in which an element is sealed with a resin and at least a surface of the radiator plate opposite to a bonding surface of the element is open, the radiator plate is made of the radiator plate described above. .

According to the present invention, there is provided a ceramic multilayer wiring board having a semiconductor element mounted on a heat sink, an external wiring connection pin, and an open space in the center for housing the element.
A metal wire for electrically connecting the element and a terminal of the substrate; joining the heat sink and the substrate so as to place the element in the space; and joining the substrate with a lid to join the element. In a semiconductor device that is shielded from the atmosphere, the radiator plate includes the radiator plate described above.

According to the present invention, there is provided a ceramic multilayer wiring board having a semiconductor element mounted on a heat sink, a terminal for connecting an external wiring, and a concave portion for accommodating the element in the center, and a terminal of the element and the substrate. And a metal wire for electrically connecting the heat sink and the recess of the substrate so that the device is installed in the recess, and the substrate is joined by a lid to shield the device from the atmosphere. In the semiconductor device, the radiator plate may include the radiator plate described above.

The present invention comprises a semiconductor element joined on a heat sink with a thermally conductive resin, a lead frame joined to a ceramic insulating substrate, and a TAB for electrically connecting the element to the lead frame. In a semiconductor device in which the heat sink and the insulating substrate are joined to block the element from the atmosphere and a heat conductive resin elastic body is interposed between the element and the insulating substrate, the heat sink is as described above. It is characterized by comprising a heat sink.

According to the present invention, there is provided a semiconductor device joined to a first radiator plate by a metal, and the first radiator plate is mounted on the ground plate of a second radiator plate joined to a ground plate. In a semiconductor device having a TAB electrically connected to terminals of the element and resin-sealing the element, the radiator plate is formed of the radiator plate described above.

According to the present invention, there is provided an electrode plate for an electrostatic attraction device, comprising the composite material described above.

According to the present invention, a voltage is applied to the electrode plate to generate an electrostatic attraction force between the dielectric plate bonded to the electrode plate and the object, so that the object is placed on the surface of the dielectric plate. The electrode plate is made of the above-described copper composite material.

The heat radiating plate and the electrode plate in the present invention can be formed into a final shape by plastic working by press after sintering or subsequent working by rolling or the like.

The copper composite material according to the present invention is 17.6 × 1
Cu having a thermal expansion coefficient of 0 ^-6 / ° C and a high thermal conductivity of 391 W / m · K, a thermal conductivity of 12 W / m · K and 2.7 × 1
A composite material of Cu ₂ O having a low coefficient of thermal expansion of 0 ⁻⁶ / ° C. and a composition of Cu-5 to 80 volume% Cu ₂ O as a sintered body composition applied to a heat sink of a semiconductor device. The thermal expansion coefficient from room temperature to 300 ° C. is 5 ×
10 ^-6 -17 × 10 ^-6 / ° C, thermal conductivity 30-375 W
/ M · K and a conductivity of 10-85% IACS. When the content of Cu ₂ O is 5% or more, the thermal expansion coefficient required for the heat sink is obtained, and when it is 80% by volume or less, sufficient thermal conductivity and strength as a structure are obtained.

In the present invention, the composite material is basically obtained by powder metallurgy. In the copper composite material of the present invention, Cu powder and Cu ₂ O powder or CuO powder are mixed at a predetermined ratio as raw material powders, It is manufactured by HIP sintering. The voids existing between the Cu and Cu ₂ O particles are crushed by the isotropic pressing force during sintering, and a sintered body having a density of 95% or more of the theoretical density is obtained. Densification is effective for improving thermal conductivity and electrical conductivity and improving plastic workability.

The constituent Cu and Cu ₂ O have low hardness,
Due to its high ductility, cold or hot working such as rolling and forging is possible, and plastic working is performed at least in either cold or hot as required. By imparting processing, the material exhibits heat conduction and electrical conduction anisotropy. However, it is effective for applications requiring strength improvement, heat transfer in a certain direction, and conductivity.

The mixing of the raw material powder is performed by a V mixer, a pot mill, a mechanical alloying, or the like.
Since the particle size of the raw material powder affects the dispersibility of Cu ₂ O during mixing and after HIP sintering, the Cu powder is 100 μm or less,
The particle diameter of Cu ₂ O and CuO powder is 10 μm or less, especially 1 μm.
２2 μm is preferred.

In the HIP sintering, the pressure is 1000 to 200.
The pressure is preferably about 0 atm, 700 ° C. to 1050 ° C. for about 3 hours, and the temperature is raised as the Cu ₂ O content increases. The sintering temperature depends on the base metal,
At 700 ° C. or lower, a sintered body having a high density cannot be obtained. At 1050 ° C. or higher, there is a risk of partial melting due to a eutectic reaction between Cu and Cu ₂ O.
00 ° C to 1000 ° C is preferred.

In the present invention, CuO is used as a raw material powder, and after mixing, filling, deaeration and sealing of Cu powder, C
By internally oxidizing u, a sintered body having a structure in which a Cu phase and a Cu ₂ O phase are dispersed can be finally obtained. That is, when CuO coexists with Cu, it utilizes the fact that it is more thermally stable to transform to Cu ₂ O at high temperature according to the equation (1).

2Cu + CuO → Cu + Cu ₂ O (1) It takes a predetermined time for the equation (1) to reach equilibrium. For example, when the sintering temperature is 900 ° C., about 3 hours is sufficient. .

The particle size of Cu ₂ O in the sintered body is preferably fine because it affects the density, strength or plastic workability. However, the particle size is strongly affected by the method of mixing the powders, and the larger the mixing energy, the less the agglomeration between the powders, and a fine Cu ₂ O phase is obtained after sintering.

In the present invention, in a V mixer having a low mixing energy, the Cu ₂ O phase has a particle size of 50 to 200 μm in 50% by volume or less of the Cu ₂ O phase and the remaining 50 μm or less,
50 μm or less in a pot mill containing steel balls,
For mechanical alloying having the largest mixing energy, the diameter is specified to be 10 μm or less. Particle size 200μm
Above, the porosity greatly increases, and plastic working becomes difficult. When the porosity is 50% by volume or more of the Cu ₂ O phase, the thermal conductivity decreases and the variation in characteristics increases, and the heat dissipation of the semiconductor device is caused. Unsuitable for board. More preferred tissue is 50 μm
This is a structure in which the following Cu ₂ O phase is uniformly dispersed with the Cu phase.
Although the Cu ₂ O particles after sintering have an irregular shape, the particles before sintering can be seen at a higher magnification because the particles before sintering are continuous. The Cu ₂ O phase is preferably 10 μm or less.

According to the present invention, there is provided a surface mounting type or semiconductor device characterized in that the semiconductor device described above is sealed with a composition containing or not containing a silicon polymer and epoxy resin, spherical quartz powder. It is a non-surface mounting type resin-sealed semiconductor device. Spherical quartz powder is 70% by weight or more of the whole composition,
More preferably, it is 80 to 95% by weight. In particular, the present invention relates to a logic or memory semiconductor device having a thickness of 1.5 m.
m is 82 to 90% by weight with respect to a thin shape having a particle diameter of not more than 90%, containing no silicon polymer, and 90% or more of the quartz powder is composed of fused spherical quartz powder, and 3 to 10% is non-spherical (square). ) Quartz powder is used.

The present invention also relates to a logic or memory semiconductor device which has a thickness of 1.5 mm or more and has a normal surface-mount type QFP, a non-surface-mount type DILP, and a memory having a SOJ or TSOP surface mount. Filler, preferably quartz powder is 75 ~
It is sealed with an epoxy resin composition having 81% and silicon. 5 μm to 1 particle size among fillers
Fused spherical quartz powder is used for 60 to 80% of the powder having a diameter of 00 μm, and it is preferable to use a rectangular quartz powder (crushed quartz powder) having a particle size of less than 5 μm, preferably 3 μm or less. The spherical quartz powder is preferably 65 to 75%.

As the resin-sealed semiconductor device according to the present invention,
It is also used for structures such as SOP, PLCC and MSP.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Example 1) As a raw material powder, 75
An electrolytic Cu powder of μm or less and a Cu ₂ O powder having a purity of 3N and a particle size of 1 to ₂ μm were used. Table 2 shows Cu powder and Cu ₂ O powder.
And then mixed in a dry pot mill containing steel balls for 10 hours or more. The mixed powder is poured into an iron container having a diameter of 30 mm and a height of 50 mm.
After vacuum degassing and welding sealing at 00 ° C., HIP sintering was performed. The HIP was applied at a pressure of 1000 atm, varied between 800 ° C. and 1000 ° C. depending on the Cu ₂ O content, and maintained at each temperature for 3 hours. Thereafter, the specimen was subjected to structure observation, density, thermal expansion coefficient, thermal conductivity, conductivity and Vickers hardness measurement. The coefficient of thermal expansion is T at room temperature to 300 ° C.
The measurement was performed using an MA (Thermal Mechanical Analysis) device, and the thermal conductivity was measured using a laser flash method, and the conductivity was measured using a sigma tester. The results are shown in Table 1.
FIG. 1 shows the microstructure of the obtained sample No. 5 HIP sintered body.

The thermal expansion coefficient, thermal conductivity and conductivity are shown in Table 1.
As is clear, by adjusting the composition ratio of Cu and Cu ₂ O, the composition changed over a wide range, and it was found that the thermal characteristics required for the heat sink could be controlled.

On the other hand, as apparent from FIG. 1 (200 times), the microstructure of Cu ₂ O agglomerates in the mixing step and grows enlarged in the sintering step, but the particle size is 50 μm or less, and a plurality of particles are formed. Cu ₂ O with complex shape connected
It has a dense structure in which the phases are uniformly dispersed. The white part in the photograph is the Cu phase, and the black part is the Cu ₂ O phase. When the Cu ₂ O particles are 30% or more, most of the particles are a lump formed by connecting a plurality of particles. When the Cu ₂ O particles are 20% or less, the lump is 10 or less per 100 μm square. Had become.

As a result of the hardness measurement, the Cu phase was Hv 75-8.
0, Cu ₂ O had a hardness of Hv 210 to 230.

[0046]

[Table 1]

The density of each sintered body was 95% or more of the theoretical density, and a higher density was obtained as compared with the case of normal pressure sintering. In particular, the effect of HIP was more remarkable as the amount of Cu ₂ O was larger.

(Example 2) Cu-55% by volume was obtained under the same conditions as in Example 1 except that the mixing of the powder was performed with a V mixer.
After preparing a Cu ₂ O sintered body, it was heated to 900 ° C.
After forging to a thickness of 1/2 with a 0-ton press and softening and annealing at 500 ° C., the microstructure, thermal conductivity and conductivity were measured in the same manner as in Example 1.

In the forged material, some edge cracks were observed on the side surface, but the other parts were sound. It was found that the copper composite material of the present invention was excellent in plastic workability.

The thermal conductivity and the electrical conductivity are shown in Table 2. The anisotropy was generated by forging, and the heat in the L direction parallel to the orientation direction (forging direction) of the Cu phase and Cu ₂ O phase. The conductivity and the conductivity showed values larger than the C direction (forging direction) perpendicular thereto.

[0051]

[Table 2]

[0052] The microstructure is Cu, which differs greatly in size.
It has a structure in which ₂ O is mixed, and 50 to 20 Cu ₂ O particles are formed by agglomeration during mixing by a V mixer.
It was a mixed structure of 0 μm size and 50 μm or less.

Example 3 As a raw material powder, an electrolytic Cu powder of 74 μm or less and a CuO powder having a purity of 3N and a particle size of 1 to 2 μm were used, and the composition ratio of Cu powder and CuO powder was Cu-22.4% by volume CuO. And 300 g in a 120 mm diameter planetary ball mill container containing 8 mm diameter steel balls.
Time mechanical alloying (MA) was performed. Thereafter, the mixed powder was poured into an iron container having a diameter of 30 mm and a height of 50 mm, and
After vacuum degassing and welding sealing at 00 ° C., HIP sintering was performed. H
The IP was performed at 800 ° C. for 3 hours at a pressure of 1000 atm. Then, it was subjected to structure observation, measurement of thermal expansion coefficient and thermal conductivity, and oxide X-ray diffraction.

FIG. 2 shows a microstructure (200 times). As is clear from the photograph, compared to FIG.
₂ O is fine and Cu ₂ O having a particle size of 10 μm or less is uniformly dispersed. Refinement of the structure is suitable for improving the strength of the sintered body and improving the cold rolling property. The density of the obtained sintered body was 96% of the theoretical density.
The density was greatly increased compared to 83% in the case of normal pressure sintering at 00 ° C. × 3 hours. As for the sintered body, the oxide was identified by X-ray diffraction. As a result, the detected diffraction peak was C
It was only u ₂ O, and it was confirmed that CuO was completely transformed into Cu ₂ O during sintering. As a result of the chemical analysis, the composition of the sintered body was Cu-40% by volume Cu ₂ O as set.

On the other hand, the thermal expansion coefficient and the thermal conductivity were equal to those of the same composition of Example 1.

Example 4 As raw material powder, electrolytic Cu powder having a particle size of 74 μm or less and CuO powder having a purity of 3N and a particle size of 1 to 2 μm were used at a composition ratio of Cu-30 vol% Cu ₂ O of 150.
After mixing 0 g, the mixture was mixed in a dry pot mill containing steel balls for 10 hours or more. Then, the mixed powder was poured into an iron container having a diameter of 60 mm and a height of 100 mm, and after vacuum degassing and welding sealing at 400 ° C., HIP sintering was performed. HIP was performed at 900 ° C. for 3 hours with a pressure of 1500 atm.
After that, microstructure observation and rollability were examined. In the rolling, the obtained sintered body was hot-rolled at 900 ° C. to a thickness of 3 mm, pickled, and then cold-rolled to a thickness of 200 μm.

FIG. 3 shows the microstructure (20
0 times), but the Cu ₂ O phase is formed by decomposition of Cu ₂ O and CuO generated by the oxidation reaction of Cu and CuO.
Although it is composed of u ₂ O and has an irregular shape due to agglomeration and growth and enlargement, the microstructure of the rolled material shows that the Cu ₂ O phase is plastically deformed in the rolling direction as shown in FIG. It is oriented and the shape is granular and fine.

[0058] (Example 5) raw material powder, with a Cu ₂ O powder of the following electrolytic Cu powder and the particle diameter 1 to 2 [mu] m 74 .mu.m, was 1500g formulated in a composition ratio of Cu-15 vol% Cu ₂ O, steel The mixture was mixed in a dry pot mill containing balls for 10 hours or more. And the mixed powder is 60m in diameter
m, and poured into an iron container having a height of 100 mm, vacuum degassed at 400 ° C., sealed by welding, and then HIP-sintered. HIP was performed at 900 ° C. for 3 hours with a pressure of 1500 atm.

FIG. 5 shows the microstructure (20
0 times), but has a structure in which granular Cu ₂ O phases of 30 μm or less are uniformly distributed.

Next, the obtained sintered body was cold-rolled to a thickness of 400 μm to examine plastic workability. Since the Cu ₂ O phase having a higher hardness is dispersed in the Cu phase, the deformation resistance is higher than that of pure Cu, and the rollability tends to be inferior. However, as shown in FIG. In addition, the Cu ₂ O phase tends to be oriented in the rolling direction, and the Cu phase, C
No defects such as cracks were observed in the u ₂ O phase and at the boundaries between them, and it was found that the copper composite material of the present invention can be made thinner by plastic workability.

Embodiment 6 An insulated gate bipolar transistor (IGBT) is used in a power semiconductor device by using the copper composite material of the present invention.
Transistor (hereinafter abbreviated as IGBT) An embodiment applied to a heat sink (base plate) of a module will be described.

FIG. 7 is a plan view showing the inside of a module having 24 IGBT elements, and FIG. 8 is a sectional view showing the module having one IGBT. Four IGBT elements 101 and two diode elements 102 are connected by solder 201 to an AlN substrate 103 in which copper foils 202 and 203 are joined to an AlN plate 204 with a silver brazing material (not shown). AlN substrate 1
03, an emitter wiring 104 and a collector wiring 105,
The region of the gate wiring 106 is formed, and the IGBT element 101 and the diode element 102
Soldered to five areas. From each element, a metal wire 1
07 is connected to the emitter wiring 104. Also,
A resistance element 108 is arranged on the gate wiring 106 region, and is connected to the resistance element 108 by a metal wire 107 from a gate pad of the IGBT element 101 which is a semiconductor element. Six AlN substrates 103 on which semiconductor elements are mounted
Is connected to the heat radiating plate 109 made of a Cu—Cu ₂ O composite material with Ni plating on all surfaces according to the present invention described in Examples 1 to 5 by the solder 205. The terminals 206 and the AlN substrate 103 of the case block 208 in which the terminals 206 and the resin case 207 are integrated
09 for wiring. Also, the case 207 and the heat sink 1
09 is connected by a silicone rubber adhesive 210. The terminals from the case block 208 have the main terminals
On the 1N substrate 103, an emitter terminal connection position 110, an emitter sense terminal connection position 111, and a collector connection terminal position 112 are respectively connected at two places, and a gate terminal connection position 113 is connected at one place. Next, a case lid 2 having a resin injection port
Silicon gel 212 so as to cover the entire terminal from 11
Is injected, and then a thermosetting epoxy resin 213 is injected over the entire surface to complete the module.

The heat radiating plate 109 is supported by eight bolt holes 114 on a supporting plate made of Al by bolts. The bolt holes 114 are drilled by machining. Furthermore, the case
Reference numeral 207 denotes the other two bolts which are connected by the adhesive 210, and is connected through the bolt holes 115.

[0064] Table a base material generally used in 3, Cu-30% by volume Cu-Cu ₂ O alloy material of the present invention Cu ₂
The thermal expansion coefficient and thermal conductivity of O 2 are shown. A semiconductor device using a Cu—Cu ₂ O-based material is a commonly used C element.
lower thermal expansion coefficient than u-based module,
The reliability of the solder 209 connecting the 1N substrate 103 and the heat sink 109 serving as a base can be improved. On the other hand, Mo and Al-SiC bases used for improving the reliability of the solder 106 under severe use environment
Although the coefficient of thermal expansion is smaller than that of a semiconductor element using a u-Cu ₂ O base, there is a problem that the thermal conductivity is small and the thermal resistance of the module increases. Cu-Cu ₂ of this example
The reliability (thermal fatigue test life) of the module equipped with the O base is more than 5 times that of the Cu base, and the thermal resistance of the module having the same base thickness is 0.8 compared to the Mo base.
It can be less than double.

[0065]

[Table 3]

With these effects, it is possible to expand the range of selection of the module structure and other members. For example, in the embodiment of FIG. 7, the Cu—Cu ₂ O alloy base material has a higher thermal conductivity than the Mo base material, in other words, the heat spreadability is improved. This has the effect of suppressing the temperature difference of the semiconductor module to a small value, and the semiconductor element is about 1.2 times larger than the conventional module. As a result, in order to secure the same amount of current in the conventional device, the structure using 30 IGBTs can be designed with 24, and the module size can be reduced. Further, it becomes possible to use an alumina substrate having a thermal conductivity smaller than that of AlN by about 20% as the insulating substrate. Alumina has higher bending strength than AlN, and can increase the substrate size. Further, since the alumina plate has a larger thermal expansion coefficient than the AlN plate and can reduce the difference in thermal expansion from the base material, the warpage of the module itself can be reduced. By using an alumina substrate, the allowable size of the substrate can be increased, so that the number of semiconductor elements that can be mounted on one substrate can be increased. That is, it is possible to reduce an area for securing insulation and an area between substrates, which are indispensable for each insulating plate, and it is possible to reduce a module size.

FIG. 9 is a schematic diagram showing a module manufacturing process according to this embodiment. (a) The Cu—Cu ₂ O radiator plate 109 is received in a substantially flat state with the surface plated with Ni.
2B, the AlN substrate 103 in which the semiconductor element 101 is joined by the solder 102 is joined by the solder 205. At this time, since the thermal expansion coefficient of the heat radiating plate 109 is larger than the composite of the semiconductor element and the AlN substrate, the back surface of the module warps in a concave shape during the cooling of the solder. (C) In the process of assembling the case block 208 with a thermosetting adhesive, the coefficient of thermal expansion of the case is larger than that of the composite body 301 after the soldering is completed, so that the module back surface becomes almost flat during the cooling of the adhesive. (d)
When the inside of the module is filled with the silicon gel 212 and the thermosetting epoxy resin 213, the back surface of the module is warped in a convex shape due to a large thermal expansion coefficient of the resin.

FIG. 10 shows the results of measurement of the amount of back surface warpage in each step. When the deformation amount is positive, the back surface is concave, and when the deformation amount is negative, the back surface is convex. When the Cu—Cu ₂ O base of the present invention is used, the amount of warpage can be suppressed to about ３ as compared with a module using a conventional Mo base. Although the results for the Cu base are not shown, the difference in expansion coefficient from the AlN substrate is large, and in the step (b), the amount of warpage is large in the direction in which the back surface is concave.
Warpage of 00 μm or more occurs. Cu-Cu _{2 of the} present invention
With the O base, the amount of warpage of the module can be reduced, so that the module can be made larger. Also, since the amount of change in the warpage due to the temperature change during the actual operation of the module is small, as in the amount of warpage in the assembly process, it is possible to suppress the grease applied to the space between the module and the cooling fins.

FIG. 11 shows an embodiment of a power converter to which the module of the present invention is applied. Power semiconductor device 50
1 is a heat dissipating grease 5 on an aluminum heat sink 511.
It is mounted with fastening bolts 512 across 10
An example in which a two-level inverter is configured will be described. Generally, the module 501 connects the intermediate point (point B) to one intermediate point wiring 5.
The circuit is mounted with the left and right reversed so that wiring can be performed at 03. Collector-side wiring 502 and emitter-side wiring 504 are U,
The power supply voltage 509 is supplied by wiring the V and W phases. The signal line is composed of each IGBT module 501 to gate wiring 505, auxiliary emitter wiring 506, and auxiliary collector wiring 507. 508 is a load.

FIG. 12 shows the warpage of the module and FIG.
2 shows the amount of warpage (grease thickness) on the back surface of the module before and after tightening when the module is mounted, (a) is the present invention, and (b) is the conventional method. A conventionally known
In the case of an l-SiC-based module, the convexity of the back surface is about 100 μm. However, when the module is coated with grease and tightened, the module is deformed by being pressed by the grease at the time of tightening. Deformation increases the grease thickness at the center and increases the contact resistance.
In contrast, in the case of the Cu—Cu ₂ O base of the present invention,
Although the initial back surface warpage is about 50 μm, the rigidity of the base material is large, so the grease thickness at the center of the module after grease is applied and tightened can be reduced to about 50 μm, and the conventional Al-SiC base Was halved compared to. Further, the variation of the grease thickness in the module can be reduced. Implementation of grease pushed deformation problem, a problem which naturally also occurs when implementing the rigidity of small Cu base module than Cu-Cu ₂ O alloy, measures in Cu-Cu ₂ O alloy of the present invention.

As shown in the figure, the Cu--Cu ₂ O of the present invention
It has been described that the alloy base can reduce the thermal resistance and the contact thermal resistance as compared with the base material such as Mo or Al-SiC used in the conventional high reliability module. As a result, the module can be mounted in a fine state as shown in FIG. Furthermore, since the cooling efficiency of the cooling fins can be reduced, the mounting area and volume of the power converter can be reduced. Further, since the grease thickness can be reduced, the allowable range of the flatness of the cooling fins can be set large, so that it is possible to assemble the power converter using large fins. Further, an auxiliary cooling function such as forced air cooling can be eliminated, and in this respect, the size and noise can be reduced.

Example 7 The copper composite material of the present invention described in Examples 1 to 5 was applied to a plastic package on which an IC shown in FIGS.
FIG. 14 shows a heat sink built-in type, and FIG. 15 shows a heat sink exposed type.

The heat radiation plate has a thermal expansion coefficient of 9 × 1 from room temperature to 300 ° C. in consideration of the thermal expansion coefficient of the mold resin.
Cu-2 so as to be in the range of 0 ^{-6 to} 14 × 10 ^-6 / ° C.
It was prepared by changing the composition within the range of 0 to 55% by volume Cu ₂ O, and subjected to machining and Ni plating.

FIG. 14 illustrates the package structure. The lead frame 31 is bonded to a Ni-plated heat sink 33 made of the copper composite material of the present invention via an insulating polyimide tape 32. The IC 34 is joined to the heat sink 33 by soldering. In addition, the Au wire 35 connects the A on the IC.
The electrode and the lead frame are connected. They are,
Except for a part of the lead frame, a mold resin 3 mainly composed of an epoxy resin, a silica filler, and a curing agent.
6 is sealed. The heatsink-exposed type package shown in FIG. 15 differs from FIG. 14 in that the heatsink 33 is exposed outside the mold resin.

With respect to the package mounted as described above, the presence or absence of warpage and cracks at the joint between the heat sink and the mold resin was observed. As a result, if the difference in thermal expansion between the mold resin and the heat radiating plate is 0.5 × 10 ⁻⁶ / ° C. or less, there is no problem, and the composition is Cu-20 to 35% by volume Cu _2.
O 2 was also suitable because of its high thermal conductivity of 200 W / m · K.

(Embodiment 8) FIGS. 16 and 17 show that the copper composite material of the present invention described in Embodiments 1 to 5 is used as heat sinks 42 and 48.
FIG. 1 shows a cross-sectional view of a ceramic package having an IC mounted thereon. First, FIG. 16 will be described. IC4
Reference numeral 1 denotes a heat sink 42 plated with Ni using a polyimide resin.
Is joined to. Further, the heat sink 42 and the package 43 made of Al ₂ O ₃ are joined by solder. The package is wired with Cu and provided with pins 44 for connection to a wiring board. The Al electrode on the IC and the wiring of the package are connected by an Al wire 45. To seal them, a weld ring 46 made of Kovar was joined to the package with Ag solder, and the weld ring and a lid 47 made of Kovar were welded using a roller electrode. FIG. 17 shows a package in which a radiation fin 48 is connected to the ceramic package of FIG.

(Embodiment 9) FIGS. 18 and 19 show TAB
A package to which the (Tape Automated Bonding) technology is applied and the copper composite material of the present invention described in Examples 1 to 5 is used for a heat sink will be described.

First, the package shown in FIG. 18 will be described. The IC 51 is joined to a heat-radiating plate 53 according to the present invention, which is plated with Ni, via a heat conductive resin 52. Au bumps 54 are formed on the terminals of the IC and are connected to the TAB 55. The TAB is connected to the lead frame 57 via the thin film wiring 56. The IC is formed by inserting a silicon rubber 58 into a ceramic substrate 59 made of Al ₂ O ₃ .
It is sealed with a frame 60 and a sealing glass 61.

FIG. 19 shows a package sealed with a resin. The IC 65 is joined with the Ni-plated heat radiating plate 67 of the present invention by the Au-Si alloy 66, and further, the copper ground plate 69 and the Ni-plated heat radiating plate of the present invention are plated with the heat conductive resin 68. 70.
On the other hand, the terminals of the IC are connected to the TAB 72 by the Au bumps 71 and are sealed by the resin 73. Here, the lead frame 57 and a part of the heat sink are exposed outside the sealing resin. TAB is an epoxy-based Ag paste 7
4 is fixed to the copper ground plate.

(Embodiment 10) FIG. 20 shows an embodiment of an MCM in which the copper composite material of the present invention described in Embodiments 1 to 5 is applied to a heat sink. The radiator plate 83 is a sintered body or one obtained by rolling the sintered body and pressing it into a predetermined shape.

The IC 81 uses an Au wire 82 to
The thin film wiring 84 formed on the plated heat sink 83 according to the present invention is connected to the thin film wiring 84, and further, the AlN is connected with an Au wire.
Are connected to the wiring formed on a package 85 made of the same and are taken out as external terminals 86. The IC section
A preform 88 made of Au-Sn is inserted between the lid 87 made of 42 alloy and the W metallized layer of the package to be joined and sealed.

(Embodiment 11) An embodiment in which the copper composite material of the present invention described in Embodiments 1 to 5 is used as a heat sink and applied to a semiconductor device in which a semiconductor element is resin-sealed.

As an example, an IGBT (Insulated Gate B)
An example of application to a resin-sealed semiconductor device equipped with a plurality of power semiconductor elements such as an ipolar transistor is shown. FIG. 21 is a sectional view showing the configuration of a semiconductor device according to the present invention. Power semiconductor elements 11 and 12 are fixed and mounted on one main surface of electrode plate 13 of a lead frame made of Cu via solder adhesive layer 14. The other main surface of the electrode plate portion 13, that is, the back surface of the main surface on which the above components are mounted, is Cu-Cu Ni-plated on the entire surface according to the present invention described in Examples 1 to 4 via the insulating layer 2. It is bonded to a heat radiating plate 6 made of a ₂ O composite material. Next, the power semiconductor elements 11 and 12 are electrically connected to the lead electrode sections 4 and 5 by the aluminum wire bonding section 15, and a part of the lead electrode sections 4 and 5 is led out as terminals to form a main circuit. Constitute.
Further, the main circuit is covered with a resin layer 1 made of an epoxy resin to form a structure, and the entire structure is made of an epoxy resin so as to expose the terminal portions of the lead electrode portions 4 and 5 and the back surface of the heat sink 6. The resin layer 3 is integrally molded and sealed.

In this embodiment, an epoxy resin material is used as the material of the resin layer 3. However, a thermoplastic resin such as a polyphenylene resin may be used. It is desirable that the resin layer 2 contains an inorganic material filler such as alumina, magnesia, and silica in order to obtain good thermal conductivity.

The heat radiation plate has a thermal expansion coefficient of 14 × from room temperature to 300 ° C. in consideration of the thermal expansion coefficient of the mold resin.
Cu- is selected so as to be in the range of 10 ^{−6 to} 17 × 10 ⁻⁶ / ° C.
It was prepared by changing the composition within the range of 5 to 20% by volume Cu ₂ O, and subjected to machining and Ni plating.

With respect to the semiconductor device mounted as described above, the presence or absence of warpage, mold resin or cracks of the element was observed. As a result, it was found that by adjusting the amount of Cu ₂ O in the heat radiating plate so that the difference in thermal expansion between the mold resin and the heat radiating plate was 0.5 × 10 ⁻⁶ / ° C. or less, mounting was possible without any problem. .

In this embodiment, an example of a semiconductor device using an IGBT element as the power semiconductor element 11 has been described. However, another type of semiconductor element such as a MOS transistor or a diode may be used. Further, a specific circuit formed by combining these plural elements, for example, a power module for an inverter may be used. Further, a passive element such as a resistor or a capacitor may be included in the circuit. These electric or electronic elements may be mounted on a circuit board such as a printed board.

In this embodiment, the type in which the heat sink is exposed to the outside of the mold resin has been described, but a package with a built-in heat sink may be used.

(Embodiment 12) FIG. 22 is a sectional view of an electrostatic chuck using the composite material of the present invention for an electrode plate.

The present electrostatic attraction device is, as shown in FIG.
It can be used as a chuck of a sputtering apparatus for processing a workpiece 90 made of a conductor or a semiconductor in a reduced-pressure atmosphere inside a vacuum processing chamber 95. When a voltage (approximately 500 V) from the DC power supply 91 is applied to the electrode 94 of the present electrostatic attraction device, an electrostatic attraction force is generated between the dielectric plate 92 and the workpiece 90, so that the dielectric plate 92 Workpiece 90 on the surface
Can be adsorbed. As the dielectric plate used in this example, the composite materials described in Examples 1 to 5 were used.

Now, in actual sputtering,
After attaching the workpiece 90 to the electrostatic chuck, the exhaust pump connected to the gas exhaust port 97 is driven,
Evacuation is performed until the internal pressure of the vacuum processing chamber 95 becomes about 1 × 10 ⁻³ Pa. Thereafter, by opening a valve attached to the gas inlet 96, the vacuum processing chamber 95 is opened.
A reaction gas (argon gas or the like) is introduced at about 10 SCCM. At this time, the internal pressure of the vacuum processing chamber 95 is 2
It is about × 10 ^-2 Pa.

Thereafter, a high-frequency power of about 4 kW (13.56 MH) is supplied from the high-frequency power supply 13 of the electrode 94 of the present electrostatic chuck.
z), the electrodes 9 of the electrostatic chuck
A plasma is generated between the electrode 4 and another electrode (not shown). The VDC and VPP of the high frequency applied voltage in this case are
2 kV and 4 kV. In addition, the electrode 9 of the present electrostatic suction device
A matching box 98 inserted between the power supply 4 and the high frequency power supply 93 is for impedance matching with the vacuum processing chamber 95 so that high frequency power is efficiently supplied to the plasma.

As a result of actually using the sputtering apparatus, the temperature of the workpiece 90 reached about 450 ° C. during the processing. No cracks were found.
This means that the use of the present electrostatic suction device is useful for improving the reliability of processing.

In addition to the sputtering apparatus, a processing apparatus for processing a workpiece made of a conductor or a semiconductor (for example, a silicon substrate) in a reduced-pressure atmosphere (so-called processing apparatus under reduced pressure), for example, a chemical vapor deposition apparatus, Physical vapor deposition equipment,
It goes without saying that the same effect of improving the processing reliability can be achieved by using the present electrostatic chucking device as a chuck for a milling device, an etching device, an ion implantation device and the like.

According to the present embodiment, it is possible to adjust the thermal expansion of the dielectric plate and the electrodes, and it is possible to improve the heat resistance. Therefore, if the electrostatic suction device according to the present invention is used as a chuck of a processing device under reduced pressure, it is possible to reduce the incidence of foreign matter due to cracks in the dielectric plate.

Even when a heater for heating is incorporated in the electrode plate or a lower portion of the electrode plate, the same effect of improving the reliability of processing can be achieved by adjusting the coefficient of thermal expansion. (Example 13) After plastic working was performed using the sintered material obtained in Examples 1 to 5, a tape for a lead frame was manufactured by cold rolling to a desired thickness. Subsequently, a lead frame for mounting a plurality of semiconductor elements was obtained by press working. In this embodiment, the lead frame 1
Reference numeral 00 is composed of a composite material of Cu and Cu ₂ O.

Since the composite material of Cu and Cu ₂ O has excellent workability, a lead frame having such a shape can be produced by a thin plate punching method. This surface was plated with Ni.

As the lead frame shape of another embodiment of the present invention, the chip mounting portion of the lead frame 100 has a higher Cu ₂ O content than the other portions of the lead frame 100. For this reason, the difference in thermal expansion coefficient from the semiconductor chip is reduced, and thermal fatigue and thermal stress can be further reduced. Also,
The content of Cu ₂ O in other parts is low or almost
, And has high conductivity, which is effective for reducing the on-resistance of the power transistor and increasing the capacity of an IC or the like.

(Embodiment 14) FIG. 23 is a perspective view of a surface-mount type resin-sealed semiconductor device in which an LSI silicon element 300 is mounted on the lead frame obtained in Embodiment 13 and sealed with an epoxy resin. . The epoxy resin 309 uses a resin having a filler described below. 305 is an Au wire, 306 is its die bonding,
307 is an outer lead, and 308 is a support bar.

The various fillers and epoxy resin compositions shown in Table 4 were kneaded with a biaxial roll heated to 80 ° C. for 10 minutes.

The composition using the obtained spherical filler has a very low melt viscosity and a large fluidity even though the gelation time is almost the same as that of the composition using the square filler.
Further, a composition containing a filler having a smaller gradient n represented by an RRS particle size diagram has a lower melt viscosity and a higher fluidity. When the n value is 0.6 or less, the melt viscosity (1
80 ° C.) is undesirably increased.

[0102]

[Table 4]

Further, a spherical filler (sphere-1) is used as the filler.
Was used to prepare 70, 75, 80 and 85% by weight of a resin composition, respectively.

Transfer molding was performed using these resin compositions, and post-curing was performed at 180 ° C. for 6 hours, and the linear expansion coefficient, flexural modulus, and thermal stress at room temperature were measured.

Further, the semiconductor element having the aluminum zigzag wiring formed on the surface is transfer-press-sealed, and subjected to −55 ° C./30 minutes⇔ + 150 ° C./30/2000.
A cycle thermal cycle test was conducted to evaluate the crack resistance of the sealing resin layer, the lead / gold wire bonding, and the connection reliability of the aluminum wiring (if the resistance value changed by 50% or more was judged to be defective). Table 5 shows the results.

According to Table 5, the composition containing a silicone polymer and containing 80% by weight or more of a filler has a linear expansion coefficient of 1.3 × 10
^-5 / ° C or less and little increase in elastic modulus. Therefore, it can be seen that the thermal stress generated in the insert is also small.

The resin-encapsulated semiconductor device using the resin composition as in this example is extremely excellent in crack resistance and wiring reliability even when subjected to a thermal shock such as a thermal cycle test. .

In this example, a spherical quartz powder having a particle size of 100 μm or less was used as 95% of the filler with respect to the resin composition containing no siloxane, and the remainder was a square quartz powder having a particle size of 10 μm or less. It was 85% by weight. In addition, spherical quartz powder having a particle size of 100 μm or less was used as 70% of the filler in the resin composition containing siloxane, and the remainder was made up of square quartz powder having a particle size of 5 μm or less, and the total was 80.5% by weight.

[0109]

[Table 5]

The RRS particle size diagram is a particle size diagram representing a particle size distribution according to the Rosin-Rammler equation (distributed by the Japan Powder Industry Association: Powder Engineering Handbook, pp. 51-53). R (Dp) = 100exp (-b · Dp n) ... (1) [where, R (Dp): cumulative weight percent of the maximum particle size to the particle size Dp, Dp: particle size, b and n: constants] RRS The gradient in the particle size diagram is the value of n in the Rosin-Rammler equation where the cumulative weight% from the maximum particle size in the RRS particle size diagram is represented by a straight line connecting two points of 25% and 75%. Say

The particle size distribution when the filler ore is finely pulverized matches the Rosin-Rammler equation, and the RRS particle size diagram showing the particle size distribution based on this equation shows an almost straight line.

The present inventors measured the particle size distribution of various fillers. As a result, 90% by weight or more of all the fillers showed an RRS particle size diagram and showed almost linearity unless special sieving was performed. It has been confirmed that the above formula is well matched.

The spherical fused quartz powder used in the present invention is a high-temperature fused quartz powder that has been previously ground to a predetermined particle size distribution and is generated from a thermal spraying apparatus using a combustible gas such as propane, butane, acetylene, or hydrogen as a fuel. Spherical ones that are fed into a flame in a fixed amount and melted and then cooled are most preferred. The above-mentioned fused quartz has a relatively small coefficient of linear expansion by itself and an extremely small amount of ionic impurities, and thus is suitable as a resin composition material for semiconductor element sealing.

90% by weight or more of the filler has a particle size of 0.5 to 1
It is preferably in the range of 00 μm. When the number of fine particles having a particle size of less than 0.5 μm increases, the ixotropic properties of the resin composition increase, and the viscosity increases and the fluidity decreases. Also,
If the number of particles exceeding 100 μm increases, the Au wire of the semiconductor element may be deformed or cut during sealing, or coarse particles may cause clogging in the mold, and resin filling failure may easily occur. is there.

Next, the gradient n shown in the RRS particle size diagram is set to 0.
It is most preferred to be 6 to 0.95, and when n is larger than 0.95, the filler becomes bulky, the particle size of the resin composition increases and the fluidity decreases. Therefore, it is desirable that n is as small as possible, but in the present invention, it is desirable that 90% or more of the filler is in the particle size range of 0.5 to 100 μm. This is the smallest possible value.

The silicone polymer used in the present invention is a polydimethylsiloxane having a functional group such as an amino group, a carboxyl group, an epoxy group, a hydroxyl group or a pyrimidine group at a terminal or a side chain.

The epoxy resin which is solid at room temperature refers to a cresol novolak type epoxy resin, a phenol novolak type epoxy resin, a bisphenol A type epoxy resin or the like as a semiconductor encapsulating material. An acid anhydride such as pyromellitic anhydride or benzophenone anhydride is used, and a curing accelerator, a flexible agent, a coupling agent,
A coloring agent, a flame retardant, a release agent, and the like can be added as needed.

This epoxy resin composition was prepared by adding 70% to each material.
The mixture can be kneaded with a biaxial roll or an extruder heated to １００100 ° C. and molded by a transfer press at a mold temperature of 160 to 190 ° C., a molding pressure of 30 to 100 kg / cm ² , and a curing time of 1 to 3 minutes.

The linear expansion coefficient of the cured product is 1.3 × as described above.
By making it as low as 10 ^-5 / ° C or less, the elastic modulus can be made small. Therefore, the deformation and disconnection of the Au bonding wire of the semiconductor element at the time of sealing are small, and the thermal stress based on the difference in linear expansion coefficient is small, so that the temperature cycle resistance, heat resistance, moisture resistance and the like are good.

By melting and spheroidizing quartz powder as a filler, the bulk is reduced and the filler is easily filled. Further, at the time of sealing the semiconductor element, it is possible to prevent the corners of the filler from damaging the element and adversely affecting the element characteristics.
Furthermore, the elastic modulus can be reduced by blending the silicon polymer, and the thermal stress caused by the difference in linear expansion coefficient can be further reduced.

[0121]

The composite material of the present invention has a remarkable effect that it has a low thermal expansion, high thermal conductivity and high plastic workability, so that the production process can be shortened and mass production becomes possible.

The composite material of the present invention has both properties because it has a mixed structure composed of a Cu phase having high thermal conductivity and a Cu ₂ O phase having low thermal expansion.
Further, the composite material of the present invention can obtain a high thermal conductivity with a low coefficient of thermal expansion by adjusting the content of both Cu and Cu ₂ O. As an application of the present invention, it can be applied to a heat sink mounted on a semiconductor device or an electrode plate of an electrostatic attraction device.

[Brief description of the drawings]

FIG. 1 shows a sample No. 5 (Cu-4) according to Example 1 of the present invention.
Optical micrograph showing the microstructure of a 0 volume% Cu ₂ O) sintered body.

FIG. 2 shows Cu-22.4% by volume according to Example 3 of the present invention.
An optical microscope photograph showing a microstructure of a CuO sintered body.

FIG. 3 shows Cu-30% by volume Cu according to Example 4 of the present invention.
An optical microscope photograph showing the microstructure of a ₂ O sintered body.

FIG. 4 shows Cu-30% by volume Cu according to Example 4 of the present invention.
_The optical microscope photograph which shows the microstructure of the surface parallel to the forging direction of the rolled material of ₂ O.

FIG. 5 shows Cu-15% by volume Cu according to Example 5 of the present invention.
An optical microscope photograph showing the microstructure of a ₂ O sintered body.

FIG. 6 shows Cu-15% by volume Cu according to Example 5 of the present invention.
_The optical microscope photograph which shows the microstructure of the surface parallel to the forging direction of the rolled material of ₂ O.

FIG. 7 is a plan view of an IGBT module according to Embodiment 6 of the present invention.

FIG. 8 is a sectional view of an IGBT module according to a sixth embodiment of the present invention.

FIG. 9 is a schematic view of a manufacturing process of an IGBT module according to Embodiment 6 of the present invention.

FIG. 10 is a diagram showing the amount of base warpage in each step of the IGBT module according to Embodiment 6 of the present invention.

FIGS. 11A and 11B are a plan view and a cross-sectional view of a power converter in which an IGBT module according to a sixth embodiment of the present invention is mounted.

FIG. 12 shows the amount of warpage of a power converter in which an IGBT module according to a sixth embodiment of the present invention is mounted before mounting the module.

FIG. 13 is a diagram showing the amount of warpage after mounting.

FIG. 14 is a sectional view of a plastic package with a built-in heat sink according to a seventh embodiment of the present invention.

FIG. 15 is a cross-sectional view of a heatsink-exposed plastic package according to a seventh embodiment of the present invention.

FIG. 16 is a sectional view of a ceramic package according to an eighth embodiment of the present invention.

FIG. 17 is a cross-sectional view of a ceramic package with heat radiation fins according to Embodiment 8 of the present invention.

FIG. 18 is a sectional view of a semiconductor device according to a ninth embodiment of the present invention.

FIG. 19 is a sectional view of a semiconductor device according to a ninth embodiment of the present invention.

FIG. 20 is a sectional view of an MCM according to Embodiment 10 of the present invention.

FIG. 21 is a cross-sectional view of a heat sink exposed plastic package according to Embodiment 11 of the present invention.

FIG. 22 is a sectional view of an electrostatic chuck according to a twelfth embodiment of the present invention.

FIG. 23 is a perspective view of a resin-sealed semiconductor device.

[Explanation of symbols]

31, 100 ... lead frame, 33, 42, 59, 1
09: heat sink, 48: heat sink, 300: LSI silicon element.

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) H01L 23/373 B22F 3/14 H // C22C 1/04 H01L 23/36 M (72) Inventor Teruyoshi Abe Ibaraki 7-1-1, Omikacho, Hitachi City Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Junya Kanada 7-1-1, Omikamachi, Hitachi City, Ibaraki Pref. Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Yasuhisa Aono 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd.Hitachi Research Laboratories Co., Ltd. 72) Inventor Yoshihiko Koike 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi, Ltd.F-term (reference) FA01 FA07 HA02 HA03 HA16 HA37 MA28 MA29 MA31 MA32 NA04 NA05 PA 11 5F036 AA01 BB01 BD01 BD11

Claims (22)

[Claims] An inorganic compound particle having a coefficient of thermal expansion smaller than that of a metal, wherein the compound particle is a complex-shaped mass in which 95% or more or 50% or less of the whole particle is connected to each other. A composite material comprising a dispersed isotropically pressed sintered body. 2. The method according to claim 1, wherein the metal particles and inorganic compound particles having a smaller coefficient of thermal expansion than the metal have 100 or less particles in a 100 μm square cross section. The compound particles are dispersed in the form of a complex shape in which a plurality of the particles are connected to each other, or the compound particles are formed of an isotropically pressed sintered body in which a plurality of the connected particles are dispersed in an amount of 10 or less per 100 μm square. Characteristic composite material. 3. A method according to claim 1, wherein said compound particles have a Vickers hardness of 300 or less and are made of an isotropically pressed sintered body. Composite materials. 4. It has a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, and has a thermal conductivity at 20 ° C. of 1 w / m · m.
The rate of increase in the average coefficient of thermal expansion from 20 to 150 ° C. per K is 0.
A composite material having a concentration of 025 to 0.035 ppm / ° C. and comprising an isotropically pressed sintered body. 5. An isotropic pressure sintering method comprising a metal and inorganic compound particles having a smaller coefficient of thermal expansion than the metal, wherein the compound particles are formed by dispersing a continuous mass in the direction of extension by plastic working. A composite material characterized by being formed of a compact. 6. Copper particles having copper and copper oxide particles, wherein the copper oxide particles have a cross-sectional area ratio of 95% or more or 50% or more of the whole of the particles.
A composite material comprising an isotropically pressurized sintered body in which a mass of less than or equal to% is dispersed in a complicated shape mass connected to each other. 7. A heat sink for a semiconductor device, comprising a composite material according to any one of claims 1 to 6. 8. A heat sink for a semiconductor device according to claim 7, further comprising a Ni plating layer on the surface. 9. A semiconductor device having an insulating substrate mounted on a radiator plate and a semiconductor element mounted on the insulating substrate, wherein the radiator plate comprises the radiator plate according to claim 7 or 8. Semiconductor device. 10. A semiconductor device comprising: a semiconductor element mounted on a heat sink; a lead frame connected to the heat sink; and a metal wire for electrically connecting the lead frame and the semiconductor element. A semiconductor device in which the heat sink is made of the heat sink according to claim 7. 11. A semiconductor device comprising: a semiconductor element mounted on a heat sink; a lead frame connected to the heat sink; and a metal wire for electrically connecting the lead frame and the semiconductor element. In a semiconductor device which is resin-sealed and has at least a surface of the heat radiating plate opposite to the bonding surface of the element being open, the heat radiating plate comprises the heat radiating plate according to claim 7 or 8. Semiconductor device. 12. A ceramic multilayer wiring board having a semiconductor element mounted on a heat sink, an external wiring connection pin, and an open space for accommodating the element in the center, and a terminal of the element and the substrate. A metal wire that electrically connects the heat sink and the substrate so as to place the element in the space, and joins the substrate with a lid to shield the element from the atmosphere. 9. A semiconductor device comprising the heat radiating plate according to claim 7 or 8. 13. A ceramic multilayer wiring board having a semiconductor element mounted on a heat sink, an external wiring connection terminal, and a concave portion for accommodating the element in the center, and the element and the terminal of the substrate. And a metal wire for electrical connection,
9. The semiconductor device according to claim 7, wherein the radiator plate and the concave portion of the substrate are joined so that the element is disposed in the concave portion, and the substrate is joined by a lid to block the element from the atmosphere. 9. A semiconductor device comprising the heat sink according to any one of the preceding claims. 14. A semiconductor device comprising: a semiconductor element joined on a heat sink by a thermally conductive resin; a lead frame joined to a ceramic insulating substrate; and a TAB for electrically connecting the element and the lead frame. In a semiconductor device in which a heat radiating plate and an insulating substrate are joined to shield the element from the atmosphere and a thermally conductive resin elastic body is interposed between the element and the insulating substrate, the heat radiating plate may be formed as described in claim 7 or 8. A semiconductor device comprising the heat sink according to any one of the preceding claims. 15. A semiconductor device joined by metal on a first radiator plate and the first radiator plate mounted on the ground plate of a second radiator plate joined to a ground plate, 9. A semiconductor device comprising: a TAB electrically connected to said terminal; and said element being resin-sealed, wherein said heat radiating plate comprises the heat radiating plate according to claim 7 or 8. 16. An electrode plate for an electrostatic attraction device, comprising the composite material according to claim 1. Description: 17. An object is fixed to a surface of the dielectric plate by applying a voltage to the electrode layer to generate an electrostatic attraction force between the dielectric plate and the object bonded on the electrode layer. 17. An electrostatic chuck according to claim 16, wherein said dielectric plate comprises the electrode plate according to claim 16. 18. A lead frame according to claim 1, having a Ni plating layer on the surface. 19. A semiconductor device comprising: a semiconductor element; a lead frame on which the semiconductor element is mounted; and a metal wire for electrically connecting the lead frame and the semiconductor element, wherein the semiconductor element is sealed with a resin composition. 19. A semiconductor device, comprising: the lead frame according to claim 1 or 18; 20. The semiconductor device according to claim 19, wherein said resin composition comprises an epoxy resin and an inorganic filler or a composition containing an epoxy resin, an inorganic filler and a silicon polymer. 21. The inorganic filler comprises spherical quartz powder,
21. The semiconductor device according to claim 20, wherein 90% by weight or more thereof has a particle size of 0.5 to 100 [mu] m. 22. The fused spherical quartz powder according to claim 2, wherein the spherical quartz powder is a fused spherical quartz powder obtained by melting quartz powder to form a sphere.
22. The semiconductor device according to 0 or 21.